Since chromatic temporal response is more sluggish than achromatic response, motion blur is a more serious problem for color than for luminance signals.
Also, the configuration is more easily manipulated and robust than achromatic conventional Savart polariscopes reported previously in probing the object with axial movement.
In this context, achromatic plumage patches are the best candidates for crepuscular signaling, as contrast is more important than color.
Because of the important role played by the visual communication in this nocturnal species, we suggest that white plumage patches (achromatic plumage patches are the best candidates for night-time signaling, when contrast is more important than color) and the timing of visual signaling may have co-evolved to maximize effectiveness of the signal.
Here, we demonstrate that LFPs recorded through the depth of the cortex respond robustly to chromatic equiluminant gratings and, similar to human perception, LFP responses have lower spatial resolution and are more low-pass for chromatic than achromatic gratings.
Achromatic condensers followed, but they are more troublesome to use because they need precise focusing, and the working distance is short.
Most of them use models of the human visual system to express the image perception as a specific pass-band filter (to be more precise, a pass-band filter for the achromatic vision and a low pass-filter for the chromatic one) [5].
The B/Y cell responses to S-cone gratings was more low-pass (mean ± SD low-cut ratio 0.998 ± 0.005, n = 10) than the response to achromatic gratings (0.754 ± 0.332, n = 10) but the difference was not significant (P = 0.12, Wilcoxon paired rank-sum test).
Single cell recordings from monkey cortex demonstrate that most cortical neurons prefer modulation along directions in color space lying close to the achromatic axis and tend to be orientation selective, while the color sensitive cortical cells (at least in areas V1 and V2) tend to be more poorly oriented and produce the same response to spatially uniform color stimulation as to gratings [7], [8].
A key component for spectroscopic circular dichroism is an achromatic 14 wave retarder functioning over the spectral range of interest.
A leukocyte is an achromatic cell of the myeloid or lymphoid lineages capable of ameboid movement, found in blood or other tissue.
